1. Field of the Invention
The invention relates to a control apparatus for a spark-ignition internal combustion engine to control a spark-ignition internal combustion engine including a fuel injection valve that injects fuel to be fed into a cylinder, a catalyst that is provided in an exhaust passage, and a spark plug.
2. Description of Related Art
The retard of ignition timing is well known, as a warm-up control of a catalyst that is provided in an exhaust system of a spark-ignition internal combustion engine. Further, Japanese Patent Application Publication No. 2008-274789 proposes that the retard quantity for the ignition timing by the warm-up control of the catalyst is decreased in the case where the alcohol concentration of the fuel to be fed into a cylinder is high ([0010]). This is intended to inhibit a situation in which the combustion becomes unstable in the case where the alcohol concentration is high.